A continuing objective in the design of ammunition, particularly for military use, is to provide ammunition that is energetic when used, but which presents very low hazard and low vulnerability to heat, flame, impact, friction, and chemical action. This is especially important in confined quarters, such as in tanks, or submarines.
Propellants having these properties, however, are usually difficult to ignite, and require a booster propellant that is usually contained in a small cavity in the main propellant charge adjacent the primer cap. This provides a certain amount of protection for the booster charge, which is more easily ignitable than the main propellant charge; and, hence, is necessarily somewhat more vulnerable to accidental ignition by heat, impact, abrasion, etc. However, performance of conventional booster charges is still somewhat unsatisfactory in this respect. For example, the commonly-used, nitrocellulose booster charge autoignites at about 356.degree. F (180.degree. C) and is quite sensitive to shock and abrasion.